>>> mocker = Mocker()
>>> obj = mocker.mock()

>>> obj.hello()
>>> mocker.result("Hi!")

>>> mocker.replay()

>>> obj.hello()
'Hi!'

>>> obj.bye()
Traceback (most recent call last):
  ...
mocker.MatchError: [Mocker] Unexpected expression: obj.bye

>>> mocker.restore()
>>> mocker.verify()
